Function mode3

mode3(
    curr: HandleItem[],
    next: HandleItem[],
    step: number,
    reversed: boolean,
    getValue: (x: number) => number,
): HandleItem[]
Mode 3 — Pushable

When a handle is dragged into an adjacent handle, it pushes that neighbour (and any further neighbours in the same direction) along with it. Handles are always kept at least one step apart.
Parameters
- curr: HandleItem[]
  The current handle state.
- next: HandleItem[]
  The proposed next handle state.
- step: number
  The slider step value used to maintain minimum separation.
- reversed: boolean
  Whether the slider is in reversed mode.
- getValue: (x: number) => number
  Function that snaps a raw number to the nearest valid step.
Returns HandleItem[]
The updated handle array after applying push logic.
- Defined in Slider/modes.ts:61